IT outage: banks, airlines and media hit by issues linked to Windows PCs

A global IT outage has caused chaos at airports, banks, railways andbusinesses around the world as a wide range of services were taken offline and millions of people were affected.

In one of the most widespread IT crashes ever to hit companies and institutions globally, air transport ground to a halt, hospitals were affected and large numbers of workers were unable to access their computers. In the UK Sky News was taken off air temporarily and the NHS GP booking system was down.

Microsoft’s Windows service was at the centre of the outage, with experts linking the problem to a software update from cybersecurity firm Crowdstrike that has affected computer systems around the world. Experts said the outage could take days from which to recover because every PC may have to be fixed manually.

Overnight, Microsoft confirmed it was investigating an issue with its services and apps, with the organisation’s service health website warning of “service degradation” that meant users may not be able to access many of the company’s most popular services, used by millions of business and people around the world.

Among the affected firms are Ryanair, Europe’s largest airline, which said on its website: “Potential disruptions across the network (Fri 19 July) due to a global third party system outage … We advise passengers to arrive at the airport three hours in advance of their flight to avoid any disruptions.”

In the US, flights were grounded owing to communications problems that appear to be linked to the outage. American Airlines, Delta and United Airlines were among the carriers affected. Berlin airport temporarily halted all flights on Monday, while in Australia, Melbourne airport advised customers it was “experiencing a global technology issue which is impacting check-in procedures for some airlines”.

A passenger at Gatwick airport, the UK’s second largest, described the scene at the travel hub as “bedlam” with staff handing out water to those stranded.

GP practices in the UK said they are unable to access patient records or book appointments due to the outage. Surgeries took to social media to report they could not access the EMIS Web system. It is understood that NHS hospitals are unaffected by the outage. The National Pharmacy Association also confirmed that UK services could be affected.

Elsewehere in the UK, Govia Thameslink Railway (GTR) – parent company of Southern, Thameslink, Gatwick Express and Great Northern – warned passengers to expect delays because of the issue. According to the service status monitoring website Downdetector, users were reporting issues with the services of Visa, BT, major supermarket chains, banks, online gaming platforms and media outlets.

Alan Woodward, a professor of cybersecurity at the University of Surrey, said the outage appeared to have been caused by an IT product called Crowdstrike Falcon that monitors the security of large networks of PCs and downloads a piece of monitoring software to every machine.

“The product is used by large organisations that have significant numbers of PCs to ensure everything is monitored. Sadly if they lose all the PCs, they can’t operate or only at a much reduced service level,” said Woodward, who added that fixing the problem could take days.

“The major frustration is that to fix the issue will require manual intervention on every affected PC. That will mean enormous delays in recovering and hence disruption for days to come,” he said.

Woodward added that an IT error was the more likely cause than a cyber-attack.

Microsoft and Crowdstrike have been contacted for comment.